Tobacco curing apparatus



A ril 25, 1950 w. T. WAGONER TOBACCO CURING APPARATUS 2 Sheets-Sheet 1Filed Oct. 1, 1946 lH V-EZH TOR Wk: IAM 771mm Mao/v52 A TTOR:

April 25, 1950 w. T wAGONER 0 v TOBACCO CURING APPARATUS #Qled Oct. 1,1946 2 Sheets-Sheet 2 IHVEHTOIQ: WILL/AM Tug/v52 l V/lao/vse PatentedApr. 25, 1950 UNITED STATES PATENT OFFICE TOBACCO CURING APPARATUSWilliam Turner Wagoner, Elon College, N. 0. Application October 1, 1946,Serial No. 700,476

3 Claims. (01. 23753) This invention relates to the curing of tobaccoand more particularly to the combination of a drying house and anassociated heating system for subjecting uncured green tobacco to theproper temperatures during the curing process.

In the production of flue-cured tobacco, the green uncured tobacco isgathered from the field and suspended within a house where it issubjected to a curing process incurring temperatures ranging upwardlyfrom 85 degrees to 200 degrees Fahrenheit over a period of approximately100 hours. If high quality tobacco is to be produced, it is veryimportant that the temperatures be carefully maintained within certainprescribed limits during each stage of the curing process in accordancewith the response of the particular type of tobacco to heat. If, forexample, a bright leaf tobacco is being cured, either an excess ordeficiency of heat for a substantial period during the early stages ofthe process will result in a darkened or discolored cured product.

Heretofore, Various heating systems, such as furnaces, oil burningunits, and combinations of furnaces and oil burning units, have beenemployed in association with drying houses for eifecting the above namedprocess. These systerms have been objectionable, due to the lack ofeconomy or difiiculty in operation, or both. In view of the hightemperatures prevailing within the house during certain curing stages,it is very desirable to locate the source of heat on the exterior toavoid the necessity of exposing the attendant to high temperatures forcomparatively long periods when regulating the heat. It is equallyimportant that a maximum amount of the heat produced on the exterior beconveyed without loss to the tobacco on the interior of the house. Wherefurnaces alone or a combination of furnaces and oil burners areemployed, the drying house floor absorbs a large portion of the heatproduced, thereby impairing the efliciency.

It is an object of this invention to provide a tobacco curing apparatuswhich will obviate the above-mentioned problems encountered with priordevices of this character.

It is another object of this invention to provide a tobacco curingapparatus wherein the combustion chamber of a heating unit extendsinwardly through a wall of the associated drying house inspaced relationto the floor of the latter to prevent an excessive amount of heatradiation from the chamber to said floor.

It is another object of this invention to provide a tobacco curingapparatus of the character described in which a heating element, such asan oil burner, is located in that portion of the combustion chamberdisposed on the exterior of the house, and in which a flue system isconnected to the inner end of the chamber whereby the heat is uniformlydistributed over the bottom area of the house and below the tobaccosuspended from above.

It is still another object of this invention to provide a heating unitfor a drying house, comprising'a hollow elongated frusto-conicalcombustion chamber having the larger end thereof disposed on theexterior and the smaller end disposed on the interior of the house, saidlarger exterior end being provided with a heating means, and the wallthickness of said chamber progressively decreasing in thickness with theincrease in distance of any portion of the wall from the heating means.

Some of the objects of the invention having been stated, other objectswill appear as the description proceeds when taken in connection withthe accompanying drawings, in which:

Figure 1 is an isometric view of a drying house and associated heatingsystem employed for curing tobacco;

Figure 2 is a sectional plan view taken through the lower portion ofFigure 1;

Figure 3 is a cross-sectional detail view taken along the line 3-3 inFigure 1, illustrating the means for varying the air draft in theheating system;

- Figure 4 is a vertical sectional detail view taken alongthe line 4-4in Figure 2, showing the relative positions of the heating system andthe suspended tobacco within the drying house;

' Figure 5 is an enlarged vertical sectional view taken along the line5-5 in Figure 2, illustrating structural details of the combustionchamber and the associated heating means; Y

Figure 6 is a sectional detail view taken alon the lines 66 in Figures 2and 5;

Figure '71s a sectional plan view taken along the line 1-4 in Figure 6,illustrating the means for vertically adjusting the position of theheating means with relation to the combustion chamberjand' Figure 8 isan'e'xploded isometricview of the combustion chamber and portions 'ofthe heating means. V

Referring more particularly to the drawings,

' the numeral I 0 broadly designates a drying house, which housecomprises sidewalls l l and I2, front wall lt,rear wall I5, floor It,and roof H, the side wall H being provided with a door l8. Suitablehorizontally disposed tier poles l9 are supported 3 by side walls H andI2 approximately seven feet above the floor l6, and these poles in turnare adapted to support a number of sticks or holders 28 having uncuredtobacco plant leaves 2! suspended thereon in the proper position to besubjected to the curing process.

As previously stated, the curing of bright leaves is usually completedwithin about 100 hours after he green leaves are gathered from thefield, and hence the application of heat is necessary. .Also, the skillwith which the attendant maintains the proper amount of heat during thevarious stages of the curing process determines to a large degree thefinal color and quality of :the cured tobacco. Furthermore, the abilityof the attendant to properly regulate the heat "is dependent upon thesensitivity and efliciency of the curing apparatus, which in the presentinstance is the combination of a drying house and a heating system.

Accordingly, a pair of horizontally disposed :frusto-conical combustionchambers 26 and 26 .have been mounted in the front wall 14 of the dryinghouse in in spaced relation to'floor it. It will be observed that bothof these chambers and their associated heating and fuel supply means aresubstantially identical. Therefore, only the chamber 26 and "associatedheating and fuel supply means will be described, and like referencecharacters with prime notations added will be applied to correspondingparts of chamher 245 and its associated structure.

The larger end of frusto-conical chamber 26 projects a short distancebeyond the exterior surface of the wall It, whereas the smaller endprojects into thedrying house a somewhat greater distance beyond theinnersurface of this same wall. Chamber 26 comprises an outer metallicIrusto-conical casing 21 which is lined with a suitable heat resistantmaterial :28 such as fire clay. The outerend of metallic casing 2.! isprovided with a lug :29 fitting into a slot 3.0 of an inspection door-34, which door is likewise provided with a lining 3-2 of fire clay orother suitable material. In order to maintain the door .3! in closedposition, suitable bolts 33.,project from "the enlarged end oftheacombustion chamber and are adapted to penetrate holes in the door 3|when the latter is closed. Wing nuts 34 on the projecting portions ofbolts 33 serve :to clamp the door in closed position. A handle 3la isprovided so that door 31 can be swung about hinge point 2-9; from boldline to dotted line position, as shown in Figure after the wing nuts 34are removed from bolts 8.3, thereby providing'access to the interior ofthe chamber from the exterior ofthe-drying house.

.By observing Figures 5 and 8i it will be seen that the lower wall:portion at :larger end-ofchamberzii has zan opening 35=therein disposedadiacent the inspection (door .31.. A heating means-is mounted :iorvertical adjustment iwithin opening :35, :said heating rmeansgpreierablycomprising an =oil burner; however, .it :is fitment that go hfilsourcescf ihea't may be -employed. This heating means comprises a heatretaining plate ajzhavl-n an outsidersizesandshapesuhstantially centeriin to opening at, zbllt somewhat ismaller' so as to provide operatingclearances 38. The central portion for" plate '31! has ea .:rectangu1aropening so therein, said plate Ibeing adapted rtoiirestmnfln theupturned flanges iof channelmembcr 14.0 55. thatwopening 39 willbecentrally positioned with .irespectztobmnercupP4,!rmountediupomthemhaninel-web :thereioelow. Theiinperrrimanortion'qo'f cup M is positioned immediately below the levelof the lower surface of the plate 31.

A U-shaped oil supply pipe 45 is provided with vertical leg portions 45aand 45b, the leg 45b leading downwardly from the central interiorportion of cup 4!, and through the web of channel member 43. Leg 451) isadiustably clamped in fixed position to a stake 46 by means of hookbolts 41, said bolts penetrating the stake and having wing nuts 48threadably secured on the projecting ends (Fig.7). By manipulating wingnuts 48, the pipe 45 and the associated burner structure designated byreference characters 31, and 44 may be adjusted vertically in thedesired positions to thereby properly space the burner with respect tothe ceiling of the combustion chamber and the opening 35.

The upper end of leg b is connected to a regulating valve 58, andleading from this valve is a comparatively flexible supply pipe 5!, theether end of the latter pipe being connected at E52 to a third supplypipe 53 (Figs. 1 and 2). Pipe 153 communicates with the interior of oilsupply tank 54 and has ashut-ofi valve .55 therein.

From the .;foregoing description it is apparent that the valve 5!! isemployed to vary the flow of oil from supply tank 154 to the burner cup4|, and hence the heat generated will vary accordingly. If the flow ofoil should be suflicient to overflow the rim of cup 41, at least aportion of the excess will be retained on the web of channel member Ali]by means of beads 40a and 401) where, the surface area of the ;flamewill be enlarged. Should the oil also overflow the beads Alto and 4th,the latter overflow will drop into pit .S'Land when ignited will serveto preheat the oil passing through U-shaped supply pipe =35, as well asto supplement the heat produced by the burner 'thereabove.

Leading from the smaller inner end of combustion chamber ,26 in parallelrelationship to :side and back walls [2 and I5 is an L,-shaped flue-pipe58. At, a point approximately at the mid portionof'the back-wall, thepipe 58 is con- 'nected to a pipe -59 which projects forwardly andslightly upwardly to a point outside the front wall M. Theprojectingendof pipe 58communisates With'the lower endof arsmoke stack65, said stack extending upwardly to a point above the house :roof 1 l.

In order tovary the draft produced by the flue system and stack -6!! asuitable draft regulator is provided, comprising a cylindrical band 6!having :an opening 'S'latherein. Band ti is rotatably mounted around thestack and has a handle .5!?) by means of which the band is roatated(Figs. '1 and .3) When the opening Sla in the band :is brought intocoincidence with the aopening 58a in the stack, the draft in the fluesystem is correspondingly diminished.

Particular attention is invited to the manner .of positioningcharnber 25in wall Hi. It will be noted that the longitudinal axis of the chamberis inclined -slightly upwardly as the latter extends into the dryinghouse,'-thereby causing the upper- ;mostiinter-ior portion of thechamber to be substantially horizontal whereas the bottom insideportioni-s inclined'to-a greater extent than the "longitudinalaxis. Suchan arrangement permits the 'iheat'produced-at the burner to readily flowintothekfiue pipe system, and also facilitates the removal of ashes,soot and the like from the :chamberwhen the inspection door 3-!isopened.

The-'frusto-conical streamlined shape of the sombustionchamberxisdesigned with a view of offering a minimum resistance to the flow of theheat currents within the chamber from the exterior to the interior ofthe drying house. At

the point where the flame is generated the heat intensity is greater,and hence there is a greater necessity for more space, as well as for athicker fire clay lining 26. At points more remote from the flame, theintensity of the heat decreases; consequently, the thickness of the fireclay and the cross-sectional area of the chamber are correspondinglyreduced. Such a construction permits substantially uniform heatradiation over the entire length of the chamber to the interior of thehouse. When an excess of heat is permitted to radiate from an area of atobacco curing flue system, the tobacco suspended directly thereabove isalso subjected to an excess of heat, resulting in scorching and damageto the cured tobacco.

In the drawings and specification there have been set forth a preferredembodiment of the invention, and although specific terms have beenemployed they are used in a generic sense and not for purposes oflimitation, the scope of the invention being set forth in the followingclaims.

I claim:

1. In a tobacco curing apparatus, the combination of a substantiallyhorizontally disposed elongated hollow member having the entire innerand outer wall surfaces thereof respectively concentric about anduniformly convergent toward a common longitudinal axis from one end tothe other of said member, the pitch of said inner convergent surfacebeing less than that of said outer convergent surface with respect tosaid axis to thereby define a wall of progressively decreasing thicknessfrom said first-named end to said other end of the member, meansproviding an opening in the lower portion of said wall and at thefirst-named larger end of said member, an

oil burner vertically positioned within said open ing along an axisdisposed substantially at right angles to said concentric axis, and anaccess door for normally closing the first-named larger end of saidhollow member.

2. Tobacco curing apparatus as defined in claim 1 wherein said inner andouter surfaces of the elongated hollow member are each frustoconicallyshaped, and wherein said access door, when closed, comprises one side ofsaid opening.

3. Tobacco curing apparatus as defined in claim 1, further comprising adrying house, one wall of said house supporting the larger and smallerends of said horizontally disposed elongated member in cantileveredpositions respectively on the exterior and interior of said house,whereby clear space is provided beneath said exteriorly located largerend for manipulation of the burner and whereby clear space is alsoprovided beneath the interiorly located smaller end to retard heatconduction to the drying house fioor.

WILLIAM TURNER WAGONER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 171,481 Millner Dec. 18, 1875337,677 Forbis Mar. 9, 1886 646,218 .I-Iollingsworth Mar. 27, 19001,077,324 Williams Nov. 4, 1913 2,223,301 Dowless Nov. 26, 1940 FOREIGNPATENTS Number Country Date 71,672 Switzerland Feb. 1, 1916

